DOCSLIB.ORG

Page - 1 Laboratory Exercise #1 - Introduction to Latitude and Longitude

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Page - 1 Laboratory Exercise #1 - Introduction to Latitude and Longitude page - 1 Laboratory Exercise #1 - Introduction to Latitude and Longitude A. Introduction There are many methods that can be used to locate ones position on the surface of the earth. A common method for location includes use of landmarks and features on the earth’s surface, which may not always provide the sufficient detail needed to confidently locate one’s position. The method that is universally accepted involves using latitude and longitude, which can provide a highly precise means for locating any place on the planet. Most formalized methods for location, such as latitude and longitude, involve using a grid system that is superimposed on the earth’s surface. B. Overview of Latitude Latitude defines location on the planet in terms of north or south (Figure 1a). Lines of latitude are also called parallels and define a full circle on the surface of the earth. Zero degrees latitude is defined as the equator, the boundary between the northern and southern hemispheres (Figure 1a). All points north of the equator are within the northern hemisphere and will always have North latitudes. All points south of the equator are within the southern hemisphere and will always have South latitudes. 90o N o Northern Northern 60 N Hemisphere Hemisphere 30o N Equator Equator 0o 30o S Southern Southern Hemisphere Hemisphere 60o S a. b. 90o S Figure 1. a) Schematic of the earth with the northern and southern hemispheres labeled. b) The earth with lines of latitude labeled at every 30 degrees. The maximum number of degrees of latitude that can be present on the earth’s surface is 90o. The North Pole has a latitude of 90o N; the South Pole is 90o S. Additionally, parallels of latitude are commonly labeled on world maps or globes normally in 15 or 30o intervals (Figure 1b). page - 2 Important terminology that will be used in lecture and later labs: Learn It ! Low Latitudes are defined as: either N or S 0 to 30o Middle Latitudes are defined as: either N or S 30 to 60o High Latitudes are defined as: either N or S 60 to 90o Realize that degrees of latitude actually equates to distance (Figure 2). Traveling one degree of latitude is equivalent to traveling approximately 60 miles. 90o N 1o N Northern Hemisphere 60 miles Equator 0o Equator 0o Southern Hemisphere 90o S Figure 2. Diagram showing the relationship between degrees of latitude and ground distance. For example, suppose you are located at a latitude of 30o N. Note that many places on the planet are also located at approximately 30o N such as Austin, TX, northern Florida, or northern Africa (Figure 3). � � � � �� � ���� � � � �� �� ����� ��� � ���� o North 30 Latitude Laredo � ���� Figure 3. World map showing different geographic places along the same parallel. page - 3 Questions: 1. What is the maximum number of degrees of latitude that can exist on the earth ? ___________ o 2. Give the latitude of the features on the earth that are the furthest away from the equator. ____________________ and _____________________ 3. What is your favorite town and what is its approximate latitude? Note: that latitude is always written in the following format: ##o N if you are in the northern hemisphere or ##o S if you are in the southern hemisphere. __________________, _______ o ____ 4. Is your favorite town located at a low, middle, or high latitude? Explain. 5. How many miles is your favorite town located away from the equator? 6. In which hemisphere (north or south) is: Australia _________________ ? North America _________________ ? 7. Can you locate yourself by just using latitude? Explain in detail. (Hint: read page 2 very carefully) C. Overview of Longitude Longitude, the second part of this locating system, defines a position on the planet in terms of east or west. Unlike parallels of latitude, which are defined by full circles, lines of longitude (or meridians, as they are also called) form half circles which go from the north to the south pole and do not encircle the whole planet (Figure 4). page - 4 90o N - North Pole 90o S - South Pole Figure 4. Globe showing meridians going from the north to the south pole. Unlike the equator, which is defined as a circle exactly halfway between the north and south pole, the zero degree meridian of longitude (the prime meridian) was arbitrarily defined. The prime meridian is a line draw from the north to the south pole and is drawn through the city of Greenwich, England; because the British were the first to formalize longitude as a measure of east-west position (Figure 5). International o 90 N - North Pole Date Line 180o o o E e 150 W 150 E a r s England e t h e p o o r 120 W n Western Eastern s 120 E i Hemisphere Hemisphere H m e o N o e m H 90 W 90 E i s n p r h e o o Prime Meridian t 60 W 60 E e s r e e 90o S - South Pole W 30o W 30o E 0o Prime Meridian Figure 5. Globes with the prime meridian, western and eastern hemispheres labeled. page - 5 Question: Are lines of longitude parallel to each other? Answer: NO. Therefore, lines of longitude are called meridians, which literally mean pie-shaped wedges (Figure 6). 90o N - North Pole 90o S - South Pole Figure 6. Diagram showing the pie-shaped nature of meridians (lines of longitude). Because meridians are not parallel to each other, the distance between adjacent meridians is different at the equator versus at the poles. For example: Meridians are located furthest away from each other at the equator. Meridians intersect with each other precisely at the poles. The distances between meridians becomes less with higher latitudes. Questions: 8. What is the maximum number of degrees of longitude that are possible? ___________ o 9. What is your favorite town and what is its approximate longitude? Note: that longitude is always written in the following format: ###o W if you are in the western hemisphere or ###o E if you are in the eastern hemisphere. __________________, _______ o ____ 10. In which hemisphere (west or east) is: Australia _________________ ? North America _________________ ? page - 6 D. Using Latitude and Longitude From the preceding discussion you should realize at this point that in the continental United States latitudes are always north and longitudes are always west (Figure 7). These facts result from the fact that the United States is north of the equator (in the northern hemisphere) and west of the prime meridian (in the western hemisphere). 60˚N 75˚N 75˚N 60˚N ARCTIC OCEAN 45˚N 45˚N 30˚N 30˚N ATLANTIC OCEAN 15˚N 15˚N PACIFIC OCEAN 120˚W 105˚W 90˚W 75˚W 60˚W page - 7 Figure 7. Map showing the continental United States in terms of latitude and longitude. Next, you should learn how to write the coordinates of latitude and longitude of a location on the earth in the correct format. Note that failure to correctly write latitude and longitude in the right format will result in a loss of points on your laboratory assignment. Latitude is always written first and longitude second as indicated below: ##o N, ###o W You not only need to write latitude and longitude correctly but also need to be able to determine the latitude and longitude of a point on a map. Refer to the map on Figure 8. The locations of points 1 to 4 on Figure 8 are as follows: Point 1 occurs on both a parallel and meridian and its location can be directly determined by examining the map. 15o N, 30o W Point 2 occurs on the equator and a meridian. The latitude on the map (equator) is defined as o0 and the longitude can be determined from the meridian on the map. 0o, 90o E Point 3 occurs on a parallel and the prime meridian. The latitude can be determined from the parallel on the map and the longitude is defined as o0 . 75o N, 0o Point 4 does not occur on either a parallel or meridian and must be determined by interpolating the latitude and longitude between the parallels or meridians. Note that on a global scale the error associated with interpolating latitude and longitude can be as great as a few degrees 5o S, 97o W 90˚N OCEAN ARCTIC ARCTIC OCEAN 75˚N 3 C 60˚N E 45˚N ATLANTIC 30˚N F D PACIFIC 15˚N PACIFIC 1 180˚W 165˚W 150˚W 135˚W 120˚W 105˚W 90˚W 75˚W 60˚W 45˚W 30˚W 15˚W 0˚ 15˚E 30˚E 45˚E 60˚E 75˚E90˚E 105˚E 120˚E 135˚E 150˚E 165˚E 180˚E OCEAN OCEAN INDIAN OCEAN 2 4 15˚S 30˚S B OCEAN A 45˚S 60˚S 75˚S 90˚S page -8 page - 9 Figure 8. World map with points labeled for homework questions. Questions: Answer the following questions by looking at the world map (Figure 8). 11. Find points A to F on Map #1. Determine the correct latitude (N or S) and longitude (E or W) of these points in degrees. A. __________________ D. _______________________ B. __________________ E. _______________________ C. __________________ F. _______________________ 12. Place a dot and the letter (I to L) on the world map (Figure 8) based on the coordinates listed below (please make the dots and letters are large enough to read). I. 0o , 100o W K. 45o S, 130o E J.
Load more

Recommended publications
  • Nicolas-Auguste Tissot: a Link Between Cartography and Quasiconformal Theory
    NICOLAS-AUGUSTE TISSOT: A LINK BETWEEN CARTOGRAPHY AND QUASICONFORMAL THEORY ATHANASE PAPADOPOULOS Abstract. Nicolas-Auguste Tissot (1824{1897) published a series of papers on cartography in which he introduced a tool which became known later on, among geographers, under the name of the Tissot indicatrix. This tool was broadly used during the twentieth century in the theory and in the practical aspects of the drawing of geographical maps. The Tissot indicatrix is a graph- ical representation of a field of ellipses on a map that describes its distortion. Tissot studied extensively, from a mathematical viewpoint, the distortion of mappings from the sphere onto the Euclidean plane that are used in drawing geographical maps, and more generally he developed a theory for the distor- sion of mappings between general surfaces. His ideas are at the heart of the work on quasiconformal mappings that was developed several decades after him by Gr¨otzsch, Lavrentieff, Ahlfors and Teichm¨uller.Gr¨otzsch mentions the work of Tissot and he uses the terminology related to his name (in particular, Gr¨otzsch uses the Tissot indicatrix). Teichm¨ullermentions the name of Tissot in a historical section in one of his fundamental papers where he claims that quasiconformal mappings were used by geographers, but without giving any hint about the nature of Tissot's work. The name of Tissot is also missing from all the historical surveys on quasiconformal mappings. In the present paper, we report on this work of Tissot. We shall also mention some related works on cartography, on the differential geometry of surfaces, and on the theory of quasiconformal mappings.
    [Show full text]
  • Mercator-15Dec2015.Pdf
    THE MERCATOR PROJECTIONS THE NORMAL AND TRANSVERSE MERCATOR PROJECTIONS ON THE SPHERE AND THE ELLIPSOID WITH FULL DERIVATIONS OF ALL FORMULAE PETER OSBORNE EDINBURGH 2013 This article describes the mathematics of the normal and transverse Mercator projections on the sphere and the ellipsoid with full deriva- tions of all formulae. The Transverse Mercator projection is the basis of many maps cov- ering individual countries, such as Australia and Great Britain, as well as the set of UTM projections covering the whole world (other than the polar regions). Such maps are invariably covered by a set of grid lines. It is important to appreciate the following two facts about the Transverse Mercator projection and the grids covering it: 1. Only one grid line runs true north–south. Thus in Britain only the grid line coincident with the central meridian at 2◦W is true: all other meridians deviate from grid lines. The UTM series is a set of 60 distinct Transverse Mercator projections each covering a width of 6◦in latitude: the grid lines run true north–south only on the central meridians at 3◦E, 9◦E, 15◦E, ... 2. The scale on the maps derived from Transverse Mercator pro- jections is not uniform: it is a function of position. For ex- ample the Landranger maps of the Ordnance Survey of Great Britain have a nominal scale of 1:50000: this value is only ex- act on two slightly curved lines almost parallel to the central meridian at 2◦W and distant approximately 180km east and west of it. The scale on the central meridian is constant but it is slightly less than the nominal value.
    [Show full text]
  • Why Do We Use Latitude and Longitude? What Is the Equator?
    Where in the World? This lesson teaches the concepts of latitude and longitude with relation to the globe. Grades: 4, 5, 6 Disciplines: Geography, Math Before starting the activity, make sure each student has access to a globe or a world map that contains latitude and longitude lines. Why Do We Use Latitude and Longitude? The Earth is divided into degrees of longitude and latitude which helps us measure location and time using a single standard. When used together, longitude and latitude define a specific location through geographical coordinates. These coordinates are what the Global Position System or GPS uses to provide an accurate locational relay. Longitude and latitude lines measure the distance from the Earth's Equator or central axis - running east to west - and the Prime Meridian in Greenwich, England - running north to south. What Is the Equator? The Equator is an imaginary line that runs around the center of the Earth from east to west. It is perpindicular to the Prime Meridan, the 0 degree line running from north to south that passes through Greenwich, England. There are equal distances from the Equator to the north pole, and also from the Equator to the south pole. The line uniformly divides the northern and southern hemispheres of the planet. Because of how the sun is situated above the Equator - it is primarily overhead - locations close to the Equator generally have high temperatures year round. In addition, they experience close to 12 hours of sunlight a day. Then, during the Autumn and Spring Equinoxes the sun is exactly overhead which results in 12-hour days and 12-hour nights.
    [Show full text]
  • Coriolis Effect
    Project ATMOSPHERE This guide is one of a series produced by Project ATMOSPHERE, an initiative of the American Meteorological Society. Project ATMOSPHERE has created and trained a network of resource agents who provide nationwide leadership in precollege atmospheric environment education. To support these agents in their teacher training, Project ATMOSPHERE develops and produces teacher’s guides and other educational materials. For further information, and additional background on the American Meteorological Society’s Education Program, please contact: American Meteorological Society Education Program 1200 New York Ave., NW, Ste. 500 Washington, DC 20005-3928 www.ametsoc.org/amsedu This material is based upon work initially supported by the National Science Foundation under Grant No. TPE-9340055. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Science Foundation. © 2012 American Meteorological Society (Permission is hereby granted for the reproduction of materials contained in this publication for non-commercial use in schools on the condition their source is acknowledged.) 2 Foreword This guide has been prepared to introduce fundamental understandings about the guide topic. This guide is organized as follows: Introduction This is a narrative summary of background information to introduce the topic. Basic Understandings Basic understandings are statements of principles, concepts, and information. The basic understandings represent material to be mastered by the learner, and can be especially helpful in devising learning activities in writing learning objectives and test items. They are numbered so they can be keyed with activities, objectives and test items. Activities These are related investigations.
    [Show full text]
  • The Equator Principles July 2020
    __________________________________________________________________________________ THE EQUATOR PRINCIPLES JULY 2020 A financial industry benchmark for determining, assessing and managing environmental and social risk in projects www.equator-principles.com 0 __________________________________________________________________________________ CONTENTS PREAMBLE ................................................................................................................................... 3 SCOPE .......................................................................................................................................... 5 APPROACH .................................................................................................................................. 6 STATEMENT OF PRINCIPLES .......................................................................................................... 8 Principle 1: Review and Categorisation .............................................................................................. 8 Principle 2: Environmental and Social Assessment ............................................................................ 8 Principle 3: Applicable Environmental and Social Standards............................................................ 10 Principle 4: Environmental and Social Management System and Equator Principles Action Plan ... 11 Principle 5: Stakeholder Engagement ............................................................................................... 11 Principle 6: Grievance Mechanism...................................................................................................
    [Show full text]
  • Map Projections
    Map Projections Chapter 4 Map Projections What is map projection? Why are map projections drawn? What are the different types of projections? Which projection is most suitably used for which area? In this chapter, we will seek the answers of such essential questions. MAP PROJECTION Map projection is the method of transferring the graticule of latitude and longitude on a plane surface. It can also be defined as the transformation of spherical network of parallels and meridians on a plane surface. As you know that, the earth on which we live in is not flat. It is geoid in shape like a sphere. A globe is the best model of the earth. Due to this property of the globe, the shape and sizes of the continents and oceans are accurately shown on it. It also shows the directions and distances very accurately. The globe is divided into various segments by the lines of latitude and longitude. The horizontal lines represent the parallels of latitude and the vertical lines represent the meridians of the longitude. The network of parallels and meridians is called graticule. This network facilitates drawing of maps. Drawing of the graticule on a flat surface is called projection. But a globe has many limitations. It is expensive. It can neither be carried everywhere easily nor can a minor detail be shown on it. Besides, on the globe the meridians are semi-circles and the parallels 35 are circles. When they are transferred on a plane surface, they become intersecting straight lines or curved lines. 2021-22 Practical Work in Geography NEED FOR MAP PROJECTION The need for a map projection mainly arises to have a detailed study of a 36 region, which is not possible to do from a globe.
    [Show full text]
  • Latitude and Longitude
    Latitude and Longitude Finding your location throughout the world! What is Latitude? • Latitude is defined as a measurement of distance in degrees north and south of the equator • The word latitude is derived from the Latin word, “latus”, meaning “wide.” What is Latitude • There are 90 degrees of latitude from the equator to each of the poles, north and south. • Latitude lines are parallel, that is they are the same distance apart • These lines are sometimes refered to as parallels. The Equator • The equator is the longest of all lines of latitude • It divides the earth in half and is measured as 0° (Zero degrees). North and South Latitudes • Positions on latitude lines above the equator are called “north” and are in the northern hemisphere. • Positions on latitude lines below the equator are called “south” and are in the southern hemisphere. Let’s take a quiz Pull out your white boards Lines of latitude are ______________Parallel to the equator There are __________90 degrees of latitude north and south of the equator. The equator is ___________0 degrees. Another name for latitude lines is ______________.Parallels The equator divides the earth into ___________2 equal parts. Great Job!!! Lets Continue! What is Longitude? • Longitude is defined as measurement of distance in degrees east or west of the prime meridian. • The word longitude is derived from the Latin word, “longus”, meaning “length.” What is Longitude? • The Prime Meridian, as do all other lines of longitude, pass through the north and south pole. • They make the earth look like a peeled orange. The Prime Meridian • The Prime meridian divides the earth in half too.
    [Show full text]
  • Social Studies Class 5 Lesson 3 Latitudes and Longitudes
    Social Studies Class 5 Lesson 3 Latitudes And Longitudes Learning Objectives; Parallels or Latitudes Important Latitudes Meridians or Longitudes Locating Places Since the Earth is spherical in shape, it is difficult to locate a place on Earth. So our mapmakers devised a system of imaginary lines to form a net or grid on maps and globes Thus there are a number of horizontal and vertical lines drawn on maps and globes to help us locate a place. Any location on Earth is described by two numbers--- its Latitude and its Longitude. The imaginary lines that run from East to West are called Parallels or Lines of Latitude. The imaginary lines that run North to South from the poles are called Meridians or the lines of Longitude. LATITUDES Lines of Latitude are east-west circles around the globe. Equator is the 0˚ latitude. It runs through the centre of the globe, halfway between the north pole and the south pole which are at 90˚. Equator 0 North pole 90˚N South pole 90˚S The Equator divides the Earth into two equal halves called hemispheres. 1. Northern Hemisphere: The upper half of the Earth to the north of the equator is called Northern Hemisphere. 2. Southern Hemisphere:The lower half of the earth to the south of the equator is called Southern Hemisphere. Features of Latitude These lines run parallel to each other. They are located at an equal distance from each other. They are also called Parallels. All Parallels form a complete circle around the globe. North Pole and South Pole are however shown as points.
    [Show full text]
  • How to Determine Latitude and Longitude from Topographic Maps
    Oregon Department of Environmental Quality HOW TO DETERMINE LATITUDE AND LONGITUDE FROM TOPOGRAPHIC MAPS Latitude is the distance north or south of the equator. 2. For each location, construct a small rectangle around Longitude is the distance east or west of the prime the point with fine pencil lines connecting the nearest meridian (Greenwich, England). Latitude and longitude 2-1/2′ or 5′ graticules. Graticules are intersections of are measured in seconds, minutes, and degrees: latitude and longitude lines that are marked on the map edge, and appear as black crosses at four points in ″ ′ 60 (seconds) = 1 (minute) the interior of the map. 60′ (minutes) = 1° (degree) 3. Read and record the latitude and longitude for the To determine the latitude and longitude of your facility, southeast corner of the small quadrangle drawn in step you will need a topographic map from United States two. The latitude and longitude are printed at the edges Geological Survey (USGS). of the map. How to Obtain USGS Maps: 4. To determine the increment of latitude above the latitude line recorded in step 3: USGS maps used for determining latitude and longitude • Position the map so that you face its west edge; may be obtained from the USGS distribution center. These maps are available in both the 7.5 minute and l5 • Place the ruler in approximately a north-south minute series. For maps of the United States, including alignment, with the “0” on the latitude line recorded Alaska, Hawaii, American Samoa, Guam, Puerto Rico, in step 3 and the edge intersecting the point.
    [Show full text]
  • Scale in GIS: What You Need to Know for GIS
    Scale in GIS: What You Need To Know for GIS Y WHAT IS SCALE? CARTOGRAPHIC SCALE Scale is the scale represents the relationship of the distance on Scale in a cartographic sense (1 inch = 1 mile) is a the map/data to the actual distance on the ground. remnant of vector cartography, but still has importance • Map detail is determined by the source scale of the data: the for us in a digital world. finer the scale, the more detail. • Source scale is the scale of the data source (i.e. aerial photo Common cartographic scales: or satellite image) from which data is digitized (into boundaries, roads, landcover, etc. in a GIS). • Topographic Maps • In a GIS, zooming in on a small scale map does not o 1:24,000 7.5” quads increase its level of accuracy or detail. o 1:63,360 15” quads • Rule of thumb: Match the appropriate scale to the level of o 1:100,000 quads detail required in the project. o 1:250,000 quads 1:500 1:1200 • World Maps o 1:2,000,000 – DCW • Shoreline o 1:20,000 o 1:70,000 Above, right. Comparing fine and coarse source scales shows how the • Aerial Photography level of detail in the data is o 1:40,000 NHAP/NAPP determined by the spatial scale of the o 1:12,000 – 4,000 custom aerial photography source data. SPATIAL SCALE GUIDELINES X Spatial scale involves grain & extent: 1. Pay attention to source scale of your spatial data. Grain: the size of your pixel & the smallest resolvable unit.
    [Show full text]
  • Maps and Cartography: Map Projections a Tutorial Created by the GIS Research & Map Collection
    Maps and Cartography: Map Projections A Tutorial Created by the GIS Research & Map Collection Ball State University Libraries A destination for research, learning, and friends What is a map projection? Map makers attempt to transfer the earth—a round, spherical globe—to flat paper. Map projections are the different techniques used by cartographers for presenting a round globe on a flat surface. Angles, areas, directions, shapes, and distances can become distorted when transformed from a curved surface to a plane. Different projections have been designed where the distortion in one property is minimized, while other properties become more distorted. So map projections are chosen based on the purposes of the map. Keywords •azimuthal: projections with the property that all directions (azimuths) from a central point are accurate •conformal: projections where angles and small areas’ shapes are preserved accurately •equal area: projections where area is accurate •equidistant: projections where distance from a standard point or line is preserved; true to scale in all directions •oblique: slanting, not perpendicular or straight •rhumb lines: lines shown on a map as crossing all meridians at the same angle; paths of constant bearing •tangent: touching at a single point in relation to a curve or surface •transverse: at right angles to the earth’s axis Models of Map Projections There are two models for creating different map projections: projections by presentation of a metric property and projections created from different surfaces. • Projections by presentation of a metric property would include equidistant, conformal, gnomonic, equal area, and compromise projections. These projections account for area, shape, direction, bearing, distance, and scale.
    [Show full text]
  • Map Projections and Coordinate Systems Datums Tell Us the Latitudes and Longi- Vertex, Node, Or Grid Cell in a Data Set, Con- Tudes of Features on an Ellipsoid
    116 GIS Fundamentals Map Projections and Coordinate Systems Datums tell us the latitudes and longi- vertex, node, or grid cell in a data set, con- tudes of features on an ellipsoid. We need to verting the vector or raster data feature by transfer these from the curved ellipsoid to a feature from geographic to Mercator coordi- flat map. A map projection is a systematic nates. rendering of locations from the curved Earth Notice that there are parameters we surface onto a flat map surface. must specify for this projection, here R, the Nearly all projections are applied via Earth’s radius, and o, the longitudinal ori- exact or iterated mathematical formulas that gin. Different values for these parameters convert between geographic latitude and give different values for the coordinates, so longitude and projected X an Y (Easting and even though we may have the same kind of Northing) coordinates. Figure 3-30 shows projection (transverse Mercator), we have one of the simpler projection equations, different versions each time we specify dif- between Mercator and geographic coordi- ferent parameters. nates, assuming a spherical Earth. These Projection equations must also be speci- equations would be applied for every point, fied in the “backward” direction, from pro- jected coordinates to geographic coordinates, if they are to be useful. The pro- jection coordinates in this backward, or “inverse,” direction are often much more complicated that the forward direction, but are specified for every commonly used pro- jection. Most projection equations are much more complicated than the transverse Mer- cator, in part because most adopt an ellipsoi- dal Earth, and because the projections are onto curved surfaces rather than a plane, but thankfully, projection equations have long been standardized, documented, and made widely available through proven programing libraries and projection calculators.
    [Show full text]